In the course of the normal metering of a liquid into a drum of barrel, a certain amount of foaming of the liquid will be experienced. The amount of foaming which takes place is normally a function of the character of the liquid as well as the temperature at which it enters the drum.
The foaming action is considerably fostered by the velocity at which incoming liquid strikes the surface of liquid already within the drum. However, even though the injecting nozzle which carries liquid into the drum is immersed beneath the surface of the contained liquid, there will still result a considerable amount of foaming.
In the filling of drums with a liquid such as lubricating oil, the characteristic of the liquid to foam during a filling action, represents a distinct disadvantge. For one thing, when a number of such drums are being filled it is necessary, as a matter of quality control, that they all have the required amount of liquid prescribed for the drum size. Preferably they will all contain equal amounts of the liquid inserted.
The usual commercial drum filling or liquid metering apparatus comprises basically, means for weighing the amount of liquid which is deposited into a drum. Thus, the weight of the combined liquid and the drum, can be monitored until a point is reached which indicates that the drum contains the prescribed amount of liquid.
During the rapid filling of drums with such a liquid as lubricating oil, there will be a strong tendency of the latter to foam within the drum depending on the pressure at which liquid is introduced. As a result, there will be a distinct propensity of the liquid to overflow through the drum's bung hole wherein the liquid carrying nozzle is normally positioned. The problem could be overcome or at least eased by reducing the flow rate at which the liquid enters the drum. This step, however, introduces an unfavorable time factor which will be reflected in the cost of the liquid.
An additional facet to be considered as above noted, drums of the type contemplated are normally filled on a weight basis. Here, the empty drum is initially positioned on a scale or other means for determining its tare weight. The filling operation then proceeds and is terminated at a point when the required amount by weight of liquid has been deposited into the drum.
Such a procedure requires that the drum then be closed by insertion of a cap member threaded into the bung opening. The drum must then be physically removed from the scale apparatus. Thereafter it can be conveyed or otherwise moved to where required. Movement of the filled drum under such circumstances is normally accomplished manually and has been found to result often times in injury to personnel due to both the awkwardness and weight of the filled drum.
Toward overcoming the above stated problems, the present invention provides a method and a metering system for liquids and particularly for relatively heavy liquids such as lubricating oil. The system includes means to both monitor, and to accurately regulate the volume of the liquid which transfers between the source thereof, and into a series of receptacles. A further feature of the system is that not only will the receptacles be efficiently loaded, but they will be provided with substantially identical quantities of the liquid being handled.
It is therefore an object of the invention to provide a liquid metering method and system, capable of rapidly dispensing substantially equal volumes of liquid into a series of receptacles. A further object is to provide a liquid metering method and system capable of dispensing the liquid while eliminating foaming action which would normally take place within the receiving receptacle. A still further object is to provide a liquid metering system of the type contemplated which includes a liquid dispensing nozzle adapted to introduce a high velocity stream of liquid into a closed receptacle while avoiding substantial foaming action within the receptacle.
The above objectives are achieved by provision of a liquid handling system which can be either automatically or manually operated. The system is capable of rapidly and sequentially metering equal amounts of the liquid into a series of containers such as drums or the like which normally include a single bung hole opening at the top side.
The present system is capable of utilizing or handling any number of liquids having varying characteristics, particularly those which exhibit a propensity for causing foaming when introduced rapidly into a receptacle. At least one liquid of the type which can be handled in the disclosed system is a conventional lubricating oil.
The latter is normally of a sufficient viscosity to readily flow when at reasonable operating temperatures between about 90.degree. F. and 120.degree. F. In the following description, the liquid being handled will be considered to be lubricating oil although no limitation as to the system's operating capabilities is to be inferred thereby. One species of such oil is characterized by a SUS viscosity at 100.degree. F. of 450.